The present invention relates to an image processing method and apparatus for generating an image from the viewpoint of an observer on the basis of images obtained from a plurality of viewpoints.
Conventionally, as an apparatus for stereoscopically displaying images viewed from a plurality of viewpoints, a stereoscopic display, a lenticular display, and the like are known. The stereoscopic display displays images which are obtained from two cameras, and which are alternately switched at a high speed. An observer can stereoscopically observe the displayed image using shutter glasses which is synchronized with the switching operation of the images or polarization glasses. In the lenticular display, images from, e.g., four cameras are re-arranged in units of pixels, and by adhering a lenticular sheet to the front surface, an image from four viewpoints can be stereoscopically expressed.
However, with the above-mentioned conventional stereoscopic display, only a stereoscopic image in the photographing directions of the cameras upon photographing of an image can be observed. More specifically, since the two cameras are fixed in position to photograph an object, an observer observes only an identical image even when he or she moves his or her viewpoint (the position of the eyes), and viewpoint movement on the observer side is not reflected in a displayed image, resulting in an unnatural image. On the other hand, the lenticular display can cope with movement of the viewpoint of the observer in the right-and-left direction, but cannot cope with continuous viewpoint movement since it allows only sequential observation of discrete images from the cameras. In addition, in the lenticular display, the viewpoint cannot be moved in the back-and-forth direction, i.e., a direction along the line of sight. A viewpoint movement in the back-and-forth direction is realized only when a stereoscopic view is achieved based on images generated by computer graphics. However, such images generated by computer graphics are special ones since they are simple and the coordinate values, in a corresponding three-dimensional space, of all the points in the images are known. For this reason, the possibility of a viewpoint movement in the back-and-forth direction has not been examined so far when images photographed by the cameras are to be stereoscopically observed.
The present invention has been made in consideration of the above-mentioned prior art, and has at its object to provide an image display apparatus and method, which can display an image from a desired viewpoint such as an image from a viewpoint which continuously moves upon movement of an observer.
It is another object of the present invention to provide an image display apparatus which generates and displays an image having the sharpness of an original image when an image is displayed from a desired viewpoint on the basis of multi-viewpoint images.
It is still another object of the present invention to provide an image display apparatus and method, which can display an image in correspondence with the position of a viewpoint even when the viewpoint moves in a direction along a line of sight which is used for generating the displayed image.
In order to achieve the above objects, an image processing method of the present invention comprises the following arrangement.
An image processing method comprises:
the detection step of detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
the first generation step of generating pixels constituting interpolated images on the basis of the detected correspondences; and
the construction step of constructing the interpolated image on the basis of the pixels generated in the first generation step.
Alternatively, an image processing method for processing multi-viewpoint images, comprises:
the viewpoint detection step of detecting a position of a viewpoint;
the generation step of generating, on the basis of the multi-viewpoint images, an image which has, as a virtual viewpoint, an intersecting point between a line of sight from the viewpoint detected in the viewpoint detection step and a viewpoint array corresponding to the multi-viewpoint images; and
the correction step of correcting a distortion of an image caused by a deviation between the viewpoint detected in the viewpoint detection step and the virtual viewpoint on the basis of an amount of the deviation.
Alternatively, an image processing method comprises:
the detection step of detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
the first generation step of generating pixels constituting an interpolated image on the basis of the detected correspondences;
the estimation step of estimating correspondences among non-processed pixels, from which correspondences cannot be detected in the detection step, between each two adjacent images of the multi-viewpoint images;
the second generation step of further generating pixels constituting the interpolated image on the basis of the correspondences estimated in the estimation step; and
the construction step of constructing the interpolated image on the basis of the pixels generated in the first generation step.
Alternatively, an image processing method comprises:
the detection step of detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
the generation step of generating pixels constituting an interpolated image on the basis of the detected correspondences; and
the construction step of constructing the interpolated image on the basis of the pixels generated in the generation step,
wherein the detection step includes the step of ignoring a correspondence between a pixel of interest and a corresponding pixel when the corresponding pixel which has the correspondence with the pixel of interest also has a correspondence with another pixel, and the number of correspondences for the pixel of interest is larger than the number of correspondences for the corresponding pixel.
An image processing apparatus of the present invention comprises the following arrangement.
An image processing apparatus comprises:
detection means for detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
first generation means for generating pixels constituting an interpolated images on the basis of the detected correspondences; and
construction means for constructing the interpolated image on the basis of the pixels generated by the first generation means.
Alternatively, an image processing apparatus for processing multi-viewpoint images, comprises:
viewpoint detection means for detecting a position of a viewpoint;
generation means for generating, on the basis of the multi-viewpoint images, an image which has, as a virtual viewpoint, an intersecting point between a line of sight from the viewpoint detected by the viewpoint detection means and a viewpoint array corresponding to the multi-viewpoint images; and
correction means for correcting a distortion of an image caused by a deviation between the viewpoint detected by the viewpoint detection means and the virtual viewpoint on the basis of an amount of the deviation.
Alternatively, an image processing apparatus comprises:
detection means for detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
first generation means for generating pixels constituting an interpolated image on the basis of the detected correspondences;
estimation means for estimating correspondences among non-processed pixels, from which correspondences cannot be detected by the detection means, between each two adjacent images of the multi-viewpoint images;
second generation means for further generating pixels constituting the interpolated image on the basis of the correspondences estimated by the estimation means; and
construction means for constructing the interpolated image on the basis of the pixels generated by the first generation means.
Alternatively, an image processing apparatus comprises:
detection means for detecting correspondences among pixels between each two adjacent images of multi-viewpoint images;
generation means for generating pixels constituting an interpolated image on the basis of the detected correspondences; and
construction means for constructing the interpolated image on the basis of the pixels generated by the generation means,
wherein the detection means ignores a correspondence between a pixel of interest and a corresponding pixel when the corresponding pixel which has the correspondence with the pixel of interest also has a correspondence with another pixel, and the number of correspondences for the pixel of interest is larger than the number of correspondences for the corresponding pixel.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.